Re: [RFC PATCH 3/3] KVM: selftests: Add vgic initialization for dirty log perf test for ARM
On Tue, 11 Jan 2022 22:16:01 +, Jing Zhang wrote: > > On Tue, Jan 11, 2022 at 2:30 AM Marc Zyngier wrote: > > > > On Mon, 10 Jan 2022 21:04:41 +, > > Jing Zhang wrote: > > > > > > For ARM64, if no vgic is setup before the dirty log perf test, the > > > userspace irqchip would be used, which would affect the dirty log perf > > > test result. > > > > Doesn't it affect *all* performance tests? How much does this change > > contributes to the performance numbers you give in the cover letter? > > > This bottleneck showed up after adding the fast path patch. I didn't > try other performance tests with this, but I think it is a good idea > to add a vgic setup for all performance tests. I can post another > patch later to make it available for all performance tests after > finishing this one and verifying all other performance tests. > Below is the test result without adding the vgic setup. It shows > 20~30% improvement for the different number of vCPUs. > +---++ > | #vCPU | dirty memory time (ms) | > +---++ > | 1 | 965| > +---++ > | 2 | 1006| > +---++ > | 4 | 1128| > +---++ > | 8 | 2005 | > +---++ > | 16| 3903 | > +---++ > | 32| 7595 | > +---++ > | 64| 15783 | > +---++ So please use these numbers in your cover letter when you repost your series, as the improvement you'd observe on actual workloads is likely to be less than what you claim due to this change in the test itself (in other words, if you are going to benchamark something, don't change the benchmark halfway). M. -- Without deviation from the norm, progress is not possible. ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [RFC PATCH 3/3] KVM: selftests: Add vgic initialization for dirty log perf test for ARM
On Mon, 10 Jan 2022 21:04:41 +, Jing Zhang wrote: > > For ARM64, if no vgic is setup before the dirty log perf test, the > userspace irqchip would be used, which would affect the dirty log perf > test result. Doesn't it affect *all* performance tests? How much does this change contributes to the performance numbers you give in the cover letter? > > Signed-off-by: Jing Zhang > --- > tools/testing/selftests/kvm/dirty_log_perf_test.c | 10 ++ > 1 file changed, 10 insertions(+) > > diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c > b/tools/testing/selftests/kvm/dirty_log_perf_test.c > index 1954b964d1cf..b501338d9430 100644 > --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c > +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c > @@ -18,6 +18,12 @@ > #include "test_util.h" > #include "perf_test_util.h" > #include "guest_modes.h" > +#ifdef __aarch64__ > +#include "aarch64/vgic.h" > + > +#define GICD_BASE_GPA0x800ULL > +#define GICR_BASE_GPA0x80AULL How did you pick these values? Thanks, M. -- Without deviation from the norm, progress is not possible. ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [RFC PATCH 3/3] KVM: selftests: Add vgic initialization for dirty log perf test for ARM
On Mon, Jan 10, 2022 at 09:04:41PM +, Jing Zhang wrote: > For ARM64, if no vgic is setup before the dirty log perf test, the > userspace irqchip would be used, which would affect the dirty log perf > test result. > > Signed-off-by: Jing Zhang > --- > tools/testing/selftests/kvm/dirty_log_perf_test.c | 10 ++ > 1 file changed, 10 insertions(+) > > diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c > b/tools/testing/selftests/kvm/dirty_log_perf_test.c > index 1954b964d1cf..b501338d9430 100644 > --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c > +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c > @@ -18,6 +18,12 @@ > #include "test_util.h" > #include "perf_test_util.h" > #include "guest_modes.h" > +#ifdef __aarch64__ > +#include "aarch64/vgic.h" > + > +#define GICD_BASE_GPA0x800ULL > +#define GICR_BASE_GPA0x80AULL > +#endif > > /* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each > loop)*/ > #define TEST_HOST_LOOP_N 2UL > @@ -200,6 +206,10 @@ static void run_test(enum vm_guest_mode mode, void *arg) > vm_enable_cap(vm, ); > } > > +#ifdef __aarch64__ > + vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA); ^^ extra parameter Thanks, drew > +#endif > + > /* Start the iterations */ > iteration = 0; > host_quit = false; > -- > 2.34.1.575.g55b058a8bb-goog > > ___ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm > ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
